In general, digital copiers, besides having copy functions such as functions for copying and printing, also come equipped with multiple other functions. Included among such digital copiers are those provided with a function for expanding image data read from a scanner or PDL data received from a host computer via a network, thereby obtaining image data, storing the image data temporarily in a storage device such as a hard disk, and repeatedly reading and printing any image data from the storage device.
In digital copiers of the kind described above, some implement a personal box function for allowing data such as a classified document that a user does not wish to be seen by others to be printed out by the user him/herself who handles the classified document, etc. The “personal box function” refers to a function whereby private image data is stored in an area specified beforehand and provided in a storage device such as a hard disk and the image data is read out of this storage area and printed if the user has been authenticated using personal authentication information such as a password.
By way of example, in a case where data relating to a classified document is created and printed out in a digital copier, the created data is stored temporarily in a previously specified area of a storage device using the above-described personal box function. The user subsequently inputs a password via a control panel on the digital copier. In response to input of the password, the data relating to the classified document is read out of the previously specified area of the storage device and is printed out. By thus utilizing the personal box function, data not wished to be seen by others can be printed out only by the user who created the data or by another user having the privilege without this data being seen by others.
With digital copiers of the kind described above, in order to avoid the area of the storage device provided in support of the personal box function from becoming so full that new data cannot be stored in this storage area, it is possible for data that has been stored in this area to be erased by the user at any time. Further, such a digital copier is so adapted that if data that has been stored in the storage device is not output within a fixed period of time, then the data is deleted automatically (for example, see the specification of Japanese Patent Application Laid-Open No. 2001-282477).
Furthermore, there is increasing demand for security enhancement in digital copiers of the above-described kind, and these copiers generally also have an encryption function for encrypting print data from a host computer and a function for enhancing the security of the hard disk per se, which constitutes the personal boxes. Moreover, there are also such copiers that have a so-called “copy-number print function” as a security function. This function has the management of output print matter as its purpose. According to this function, when a plurality of copies of a document are printed, a specific position on the printed surface is printed with a number whereby the number of the copy of this printed matter can be distinguished, thereby facilitating post-output document management. Further, the starting number or printed position of a copy number can be specified using a printer-driver UI (user interface) or control panel, whereby a value obtained by counting up from a specified number is printed as the copy number.
Personal boxes can be used in a variety of ways. For example, a plurality of personal boxes can be assigned to respective ones of users who utilizes a digital copier and a specific job can be stored via a host computer or scanner in the area assigned to each user, thereby making it possible to utilize this personal box as an information delivery box.
However, the following problems arise when an identical job of the above-mentioned kind is stored in a plurality of boxes:
(1) Management of output matter is difficult. That is, when printed matter consisting of identical data that has been stored in a plurality of personal boxes arrives, it is difficult to specify the personal box that was the source of the printout. Further, since the administrator of data at the moment the data arrives in a personal box is the administrator of the respective personal box, a limitation cannot be imposed upon the number of output copies at the source of the output.
(2) Owing to storage of data (e.g., image data, etc.) generated from the same job in a plurality of personal boxes, the storage capacity of the hard disk is exploited unnecessarily.